After excavating over 5,000 root collars, it has been discovered that 99% of transplanted trees require corrective work. Girdling roots have been observed in trees that have been over-mulched or planted too deeply. The AirKnife makes it easy to find these problem roots so they can be quickly removed.

In addition to girdling roots, other excavations have shown trees planted without removing synthetic burlap, synthetic twine or wire baskets. All are stressful to the tree by limiting root growth or girdling the growing trunk. It is also possible to diagnose problems with diseases such as Ganoderma root rot; trees planted too deeply; and those with under-sized root balls or skewed root systems.

Soil compaction is widely recognised as one of the most significant stresses associated with trees in urban environments, especially in association with development, while also being an issue in well used parks and gardens. The compacted soils have lost macro pore spaces that normally hold air and water. This has a dramatic influence on respiration and severe compaction can suffocate a tree.

The most effective treatments for compaction have been vertical mulching and radial trenching. Traditionally this has been done with spades, augers, trenchers and backhoes, balancing the increased pore space against root damage caused by these mechanical diggers.

Since the AirKnife does not damage roots, we can now double the treated area without overstressing the tree. Radial trenching to improve root growth is made easy when you can simply blow the dirt away and replace it with improved soil. In addition, vertical mulching with an AirKnife can be four times faster than with a petrol driven auger and with a lot less effort.

“The health of man, beast, plant and soil is one indivisible whole,
the health of the soil depends on maintaining its biological balance…..”
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Rob Hayward, Horticultural Development Officer, The Soil Association. -